Taken by Frank from the 1970s to the present, the Polaroids doze with the kind of mundane atmosphere prevalent in so many pictures today, the era of application-riddled smartphones and pocket-sized digital point-and-shoot cameras.

In short, the Polaroids do not look like a major deal: quick snapshots of friends, private moments, self-portraits, interiors, a view through a window. Many are grainy, some even appear out of focus, haphazard.

But look closer: Frank's pictures are striking because of their skewed camera perspectives of everyday subject matter. These photos argue that -- in the right hands -- the humdrum goings-on of our daily lives can be the poetry for high art.

Take the unpolished image of a tree in a parking lot of what looks like a strip mall. It's a subject an amateur like myself might have noticed while driving through the lot after dropping off shirts at the dry cleaners. But that doesn't mean I could have taken a picture of it as fascinating as Frank's.

And that's his brilliance. Frank's is an approach that's appropriately below-the-radar casual, a style that suggests maybe the rest of us could have taken these photos, too.

You can see how photos like Frank's have become part of the fabric of today by looking at any newspaper or magazine. Or online.

Many of us post pictures taken daily on blogs, social networking sites such as Facebook or on such photographic sharing sites as Picasa. Probably multiple photos, too, not just one. And those pictures are usually of the banal goings-on in our lives, whatever strikes our whim: a meal at a restaurant, a social gathering, someone or something noticed while crossing the street.

Technology is giving us the tools to take such pictures quickly and easily. But it was Frank and other photographers like him who showed us where and how to point the smartphone or camera.

In Frank's case, the revolution didn't begin with the Blue Sky photographs but well before them.

After initial hostility, critics and historians warmed up to the book and hoisted a legacy upon Frank that he has alternately embraced and tried his best to elude. His work, say his most ardent champions, vaulted into the American consciousness a kind of documentary street photography that we take for granted today.

But Frank was far from the first documentary-style photographer -- there were many, many others before him, including Henri Cartier-Bresson and his mentor, Walker Evans, plus dozens of Frank's similarly accomplished peers such as

Maybe it's fairer to say that Frank and his book happened at the right time: "The Americans" caught a special moment in America and in the development of photography, a zeitgeist. And part of it had to do with Frank's personal story.

Cover of "The Americans" by Robert Frank

In 1947, the Swiss-born Frank immigrated to the United States. Eight years later, he used money from a Guggenheim Fellowship to drive across his adopted country and take oodles of pictures. His task was to try to capture on film no less than the very spirit of America. But a kind of America that people during the Eisenhower Era hadn't yet recognized or seen widely through pictures.

In those two years, Frank took more than 28,000 pictures. Eighty-three of them became a book that was skewered by some critics upon publication. Why?

At the time, photographs weren't so widely disseminated the way they are now with the Internet. And with some exception, the controlling perception of America portrayed through magazine and newspaper photos was of an idealistic, heroic place captured, appropriately, in classically constructed pictures.

Frank's pictures -- and others like them by his peers -- worked against this perfectly proportioned ideal in style and substance. They were blurry, sometimes oddly cropped and composed. And they portrayed the layers of social and political division within our country, as well as just plain Americans -- people of color, loners, lovers and outcasts caught in moments not often put on film.

In short, the book caught the daily rhythms and theater of American life.

Today, "The Americans" would hardly wrinkle shirt collars because we've so thoroughly accepted the style and substance of this kind of photography. Many nonprofessionals with smartphones or digital cameras work in Frank's style even though they are unaware of Frank or the history of that photographic progression. Those of us who are aware, do so at the risk of hubris.

While looking at Frank's Polaroids at Blue Sky, for example, I thought for a moment: I could have taken these.

But, really, could I? It's a question that brings into focus issues of art and professionalism in this digital age: What separates the professional from the amateur?

says digital technology may have many more people taking pictures but that doesn't change what constitutes a photographer or a good photograph.

"It's an issue of intention," says Dolan. "That's what separates us from Robert Frank. I can make a grocery list, for example, but that doesn't mean it's a Pulitzer Prize-winning poem."

Dolan also thinks it's a tad grandiose to assume this is photography's democratic era.

"Photography has always been available to the masses," she says. "That was true way back even in the 19th century. Digital technology has just amplified that perception and added new abilities for us."

Intention, as Dolan meant it, suggests a few things: a knowledge of photographic technique and composition, and also photographic history. That means the best pictures have a larger design behind them, a skill that often eludes amateurs.

The story, called "Robert Frank's Unsentimental Journey," follows Frank on a trip to China and ends with some personal observations that reveal a photographic legend with unsparing bitterness toward loved ones, himself, his art and photography as a whole.

"There are too many images," Frank says about how digital technology has changed photography. "Too many cameras now. We're all being watched. It gets sillier and sillier. As if all action is meaningful. Nothing is really all that special. It's just life. If all moments are recorded, then nothing is beautiful and maybe photography isn't an art anymore. Maybe it never was."

Maybe Frank believes society is experiencing photographic overload.

Or maybe his stark reproach is a reminder that feast and famine can be partners in this profligate photographic heyday. Frank, now 87, continues to keep his artistic intentions lean and hungry by pushing back against the legacy that has defined photographic practice for 50 years.

For the millions of us with smartphones and little pocket cameras, he still has much to show us.